Control apparatus for vibration driven motor

Abstract

A control apparatus for a vibration driven motor, which obtains a driving force by forming a vibration wave upon application of a frequency signal to electro-mechanical converting elements. The control apparatus includes a pulse oscillation circuit, a counter for counting pulses from the pulse oscillation circuit, and a data set circuit for setting numerical value data. Every time the count value of the counter coincides with the data set in the set circuit, an output is generated, and the control circuit controls the frequency of the frequency signal according to the frequency of the generated output.

What is claimed is: 
     
       1. A control apparatus for a vibration motor which obtains a driving force upon application of a frequency signal to electro-mechanical energy converting elements, comprising: an oscillation circuit for outputting a signal;   a first counter circuit for counting a number of signal pulses of the signal output from said oscillation circuit, and for generating an output signal when a predetermined number of signal pulses are counted;   a second counter circuit for counting a number of signal pulses of the signal output from said oscillation circuit in response to the output signal from said first counter circuit;   a data circuit for setting data;   a control circuit for generating an output when a count value from said second counter circuit becomes a value according to a data value from said data circuit; and   a frequency signal forming circuit for forming a frequency signal on the basis of the output from said control circuit.   
     
     
       2. An apparatus according to claim 1, wherein said first and second counter circuits transit to an initial state every time an output is generated from said control circuit. 
     
     
       3. An apparatus according to claim 1, further comprising a data shift circuit for time-serially changing the data set by said data circuit. 
     
     
       4. An apparatus according to claim 2, further comprising a data shift circuit for time-serially changing the data set by said data circuit. 
     
     
       5. An apparatus according to claim 3, wherein said data shift circuit sequentially increases the data value set by said data circuit. 
     
     
       6. A control apparatus for a vibration motor which obtains a driving force upon application of a frequency signal to electro-mechanical energy converting elements, comprising: an oscillation circuit for generating a signal;   a first counter circuit for counting a number of signal pulses of the signal generated by the oscillation circuit, and for generating an output signal when a predetermined number of signal pulses from said oscillation circuit are counted;   a monitor circuit for monitoring a signal from said oscillation circuit in response to the output signal from said first circuit;   a data circuit for setting data;   a control circuit for generating an output when the number of signals monitored by said monitor circuit becomes a value according to data from said data circuit; and   a frequency signal forming circuit for forming a frequency signal on the basis of the output from said control circuit.   
     
     
       7. An apparatus according to claim 6, wherein said first and second counter circuits transit to an initial state every time an output is generated by said control circuit. 
     
     
       8. An apparatus according to claim 6, further comprising a data shift circuit for time-serially changing the data set by said data circuit. 
     
     
       9. An apparatus according to claim 7, further comprising a data shift circuit for time-serially changing the data set by said data circuit. 
     
     
       10. An apparatus according to claim 8, wherein said data shift circuit sequentially increases the data value set by said data circuit. 
     
     
       11. A control apparatus for a vibration motor which obtains a driving force upon application of a frequency signal to electro-mechanical energy converting elements, comprising: an oscillation circuit;   a control circuit having a first mode for generating an output during a period in which said oscillation circuit outputs a first predetermined number of signals, and a second mode for generating an output during a period in which said oscillation circuit outputs a second predetermined number of signals equal to a sum of the first predetermined number of signals in the first mode and a preselected number of signals;   a frequency signal forming circuit for forming a frequency signal having a frequency according to the output from said control circuit; and   a switching circuit for switching a mode of said control circuit between the first and second modes at each predetermined timing.   
     
     
       12. An apparatus according to claim 11, wherein when the output in the first mode is output a predetermined number of times, said switching circuit selects the second mode, and when the output in the second mode is output a predetermined number of times, said switching circuit selects the first mode.